“Facebook has had a huge impact on the social, emotional and cognitive development of young people,” says Steyer, an expert on media and children’s issues, who is concerned about how social networking affects children and teens’ brain development. “It’s time to have a serious discussion about this.” Steyer founded and runs non-profit educational group Common Sense Media and is working to kick that discussion into higher gear with his new book “Talking Back To Facebook: The Common Sense Guide To Raising Kids In The Digital Age.”

He boils down his biggest concerns into what he calls RAP:

R is for relationships. Facebook and other social networks are altering the way that young people communicate with friends, parents, teachers. They’d rather “Facebook” someone or send a text than talk, even if they’re in the same room. What does that do for teenagers’ ability to hold intelligent conversations?

A is for addiction and ADHD. Steyer advocates setting limits to time spent on social networks like Facebook. Parents have to model this behavior, too, and not be tethered to cell phones at all times.

P stands for Privacy. “So many kids self-reveal before they self reflect,” says Steyer. Teenagers aren’t always mature enough to know what NOT to share with their friends online. Steyer polled the students at Stanford, where he teaches a couple courses, and found that 70% had posted something they now wish they hadn’t. The message: Think before you share or send. “I see a big change in the attitudes of young people, a slow awakening to the critical importance of privacy,” he adds.

One big gripe that Steyer has with Facebook: Why doesn’t it have an eraser button? Yes, you can delete posts on Facebook and other social networks. But Steyer says it's 1) not easy to find the tools to delete posts 2) those tools are not easy to use and 3) the tools need to be simpler and take into account that what makes sense for a 24 year old may not be as clear to a 14 year old using the site.

“Mark Zuckerberg has said his motto is move fast and break stuff. That’s fine if you view the world as an engineer. But that motto doesn’t sit well for teenagers who are essentially forming their identities in public,” warns Steyer. Not to mention the estimated 6 million kids under age 13 who have Facebook accounts. They're even more vulnerable, says Steyer.

One of my colleagues has a college-age daughter who tried to "de-Facebook" to get away from the constant pull of the site. But so much information about where friends plan to meet and socialize and even academic assignments are on Facebook that she found she couldn't easily get off Facebook.